1. Field of the Invention
The present invention relates to an electric junction box mounted to a vehicle and the like, particularly relates to an electric junction box provided with a relay mount portion and a bus bar for conduction with the relay mount portion.
2. Description of Related Art
Electric junction boxes, such as relay boxes, fuse boxes, and the like, are conventionally used in vehicles and the like, in order to improve efficiency of electric wiring and maintenance performance. Electrical components, such as relays, fuses, and the like, and conducting members, such as bus bars and the like, are appropriately mounted to an electric junction box. Electric power from a battery and the like is thus supplied to vehicle electrical components.
An electric junction box to which a relatively large electric current is supplied, such as a relay block and the like provided proximate to a battery, has a relatively wide bus bar as a conducting member. In order to mount a wide bus bar while preventing enlargement of the electric junction box, a vertical bus bar is conventionally employed, the vertical bus bar being housed perpendicular to a surface to which a mount portion for electrical components, such as a relay and a fuse, is provided. Such a vertical bus bar is disclosed in Japanese Patent Laid-open Publication No. 2005-253158, for instance.
When the vertical bus bar as described above is employed, however, it is unavoidable that a housing portion of the vertical bus bar is significantly projected externally on a rear side of the mount portion for electrical components, and thus it is difficult to ensure a work space. Specifically, a second end side of terminal connection holes is provided open on the rear side of the mount portion for electrical components, the holes being inserted with terminals of the electrical components to a first end side thereof. When the housing portion of the vertical bus bar is provided projecting proximate thereto, the housing portion of the vertical bus bar interferes when connection terminals of external wires are inserted to the terminal connection holes, thus making the insertion work difficult.
When two fuses are provided adjacently, it is proposed that housing portions of vertical bus bars be provided on both external sides of two fuse mount portions, as shown in FIG. 3 of Japanese Patent Laid-open Publication No. 2005-253158, and thereby a work space is ensured for connection of external terminals to terminals on both internal sides.
The structure above is effective in a case in which fuses having two terminals are provided adjacently. It is difficult, however, to apply the structure to a relay having numerous terminals. Particularly in case of the relay having numerous terminals, a terminal requiring a large electric current input is sometimes provided in a middle portion of a projected surface of relay terminals. When the housing portion of the vertical bus bar is provided to the middle portion of the projected surface of the relay terminals in order to supply power to the terminal in the middle portion, the work space for connection to terminals provided nearby is thus significantly limited.